The invention refers to a rewinding machine for the production of logs of web material which have no core for the winding thereon. Neither does the winding machine have a shaft on which the web is wound.
More in particular, the invention refers to a rewinding machine including: a first winding roller, onto which the web material is fed, and a second winding roller, rotating in the same direction as the first winding roller, which form a nip through which the web material passes; means for moving the surfaces of said winding rollers close to each other; and means for severing said web material at the end of the winding of a log and at the beginning of the winding of the next log.
The invention further refers to a method for the production of rolls or logs of web material wound without central core.
A rewinder of the described type is disclosed in Italian Patent No. 1.201.220. The rewinder constructed according to that patent has some difficulties on the initial stage of the winding.
The invention refers to a new rewinder and to a new method which overcome the drawbacks of these prior art machines.
A first object of the present invention is to provide a rewinder of the type mentioned above, wherein the winding of a log will start in a safe and reliable manner.
A further object of the present invention is to provide a rewinder in which, during the initial stage of the formation of a log, when the free leading edge of the web material begins to wind up on itself to form the initial turns of the log, the log will not tend to move out of the winding nip between the two rollers.
Since the winding begins at the leading edge of the web material itself, without a stiff tubular core or shaft to facilitate the start of the log winding, there is a need to align the log being formed with the axes of the winder rollers. The present invention provides a solution to this problem by enabling the log to immediately position itself in parallel to the axes of the winding rollers.